The world’s biggest fertilizer company just dropped a hint about the reasoning for its surprise CEO departure and leadership changes earlier in the year as a “necessary” step.

Nutrien Ltd. said in its annual report that it “made the difficult decision to part ways” with former Chief Executive Officer Mayo Schmidt in January.

“We recognize this decision and others related to executive leadership have created uncertainty,” the Canadian company’s Chairman Russ Girling said in the report.

“However, these changes have not distracted our team from delivering exceptional results and we are confident these decisions were both necessary and in the best long-term interest of the company and its shareholders.”

Schmidt abruptly departed from the company after just eight months at the top job in January, baffling investors. The company had previously declined to explain the reason for the switch on multiple occasions.